testo 6740
Instruction manual
en
Preface
Preface
Preface
Dear Testo Customer
Congratulations for choosing a Testo product. We hope that you will enjoy many
years of using the product and that it will help you in your work.
If problems should occur which you cannot rectify yourself, please consult our
service department or your dealer. We will endeavour to provide fast and competent
assistance to save you long periods out of operation.
3
General information
4
General information
This Instruction manual contains important information about the features and use of
the product. Please read this document through carefully and familiarise yourself with
the operation of the product before putting it to use. Keep the Instruction manual to
hand so that you can refer to it when necessary.
Pictograms
This product could be dangerous if operated incorrectly. Information that requires
particular attention is identified in this Instruction manual by pictograms:
Warnings are identified by means of a warning triangle. The relevant signal word!
indicates the degree of risk:
Warning! means: Serious physical injury could occur if you do not take
the precautionary measures indicated.
Signal word!
Caution! means: Slight physical injury or material damage could occur
if you do not take the precautionary measures indicated.
Pay particular attention to warnings and take the precautionary
measures indicated in order to avoid danger.
Notes on special cases and peculiarities in the handling of the product are
indicated by an exclamation mark.
Standards/Approvals
According to the conformity certificate, this product fulfills all
2014/30/EU guidelines.
5
Contents
Contents
Preface..................................................................... 3
General information ................................................. 4
Contents................................................................... 5
1. Basic safety information ........................................... 6
2. Intended use ............................................................ 7
3. Product description................................................... 8
3.1
3.2
3.3
3.4
System components................................................. 8
Operating elements ................................................. 8
Settings ................................................................... 9
Current output intervals............................................ 9
4. Initial operation....................................................... 10
4.1
4.2
4.3
Mechanical assembly ............................................ 10
Electric connection ............................................... 12
Analog output / Limit signal outputs ...................... 14
5. Menu guide (0555.6743 / 0555.6744 only)............. 16
6. Adjustment on site.................................................. 18
7. Care and maintenance........................................... 19
8. Troubleshooting...................................................... 20
9. Technical data ....................................................... 21
9.1
9.2
9.3
Measurement ranges and accuracies ................... 21
Additional instrument data ..................................... 21
Uncertainty pressure dewpoint temperature.......... 22
10. Accessories / Spare parts....................................... 23
6
1. Basic safety information
1. Basic safety information
Avoid electrical hazards:
Never take measurements with the instrument and its probes on or near live
components unless the instrument is expressly approved for current and voltage
measurements.
Protect the instrument:
Never store the unit together with solvents (e.g. acetone).
Preserving product safety/warranty entitlement:
Operate the instrument only within the parameters specified in the Technical data.
Handle the instrument appropriately and according to its intended purpose.
Never apply force!
Temperature data on sensors/probes refer only to the measurement range of the
sensors. Do not subject handles and lines to temperatures greater than 70°C if
they are not expressly approved for higher temperatures.
Open the instrument for maintenance and repair purposes only if specifically
described in the Instruction Manual.
Maintenance work should only be carried out if described in the Instruction Manual.
Please adhere to the steps described. For safety reasons, please only use spare
parts from Testo.
Any additional work should only be carried out by authorised trained personnel.
Otherwise Testo does not accept responsibility for the functioning of the instrument
following maintenance and for the validity of approvals.
Dispose of carefully:
Once its service life has come to an end, return the instrument to us and we will
dispose of it.
2. Intended use
2. Intended use
The instrument is intended for use in the following applications:
The testo 6740 instrument is a pressure dew point transmitter for measuring trace
humidity. It is used in the following areas:
- Monitoring trace humidity in compressed air systems
- Controlling and monitoring (compressed air) driers.
- Monitoring humidity and temperature in medical compressed air or
granulate driers.
Application in hazardons areas is not allowed!
7
3. Product description
3.1 System components
8
3. Product description
3.1 System components
G½, without display
0555.6741
Cooling
coil 1
0554.3304
To
process
1
1
2
G½, with display
0555.6743
To PLC/
control/
analysis unit
Max. pressure: 15barabs
1Standard quick-release device
2 G½ thread
1
2
Only required for process
temperatures > 50°C, cooling coil
only in connection with measurement
chamber
Measurement chamber only required
if
- incoming flow is to be increased
(measurement chamber
guarantees a minimum incoming
flow of 1l/min at a positive pressure
of 6bar).
-fast assembly/dismantling of
transmitter without interrupting
process is required.
Standard plug, 4 to 20mA
(included with all instruments)
Accessories:
0554.3302 plug (4 to 20mA,
2 switch contacts, 2 LEDs)
NPT½“, without display
0555.6742
NPT½“, with display
0555.6744
Max. pressure: 50barabs
3.2 Operating elements
The instruments with the article numbers 0555.6741
and 0555.6742 do not have any additional operating
elements.
The instruments with the article numbers 0555.6743
and 0555.6744 have a keypad and a display to input
and read off settings (See 5. Menu guide, p. 15).
3. Product description
3.3 Settings
9
3.3 Settings
The parameters in the instrument are assigned the
following values in the factory (default values):
Parameter
Pressure dew point 1
Atmospheric dew point 1
Relative humidity
Temperature
Absolute humidity
Unit
4mA
20mA
LS
US
Hyst
°Ctp
-60
30
4
12
2
°CtA
-60
30
4
12
2
%rF, %rh, %Hr
0
100
30
50
2
°C
0
50
10
30
2
ppmv
0
30000 2
8400
13000
20
°Ftp
-75
85
40
55
2
°FtA
-75
85
40
55
2
°F
32
120
50
85
2
mg/m3 (Abs)
0
30000 2
7000
9600
20
1
With dew point temperatures <0°Ctp / <0°CtA / <32°Ftp / <32°FtA the frostpoint temperature (dewpoint upon
ice) is displayed
2 Display is shown to the power of ten: 30E3 (corresponds to 30 x 103 = 30 x 1000 = 30000)
3.4 Current output intervals
Failure information A
Measurement information M
Failure information A
4. Initial operation
4.1 Mechanical assembly
10
4. Initial operation
4.1 Mechanical assembly
We recommend you wrap the thread of the process
connection in sealing tape (e.g. PTFE) or place it in
a copper gasket (inner diameter: 21mm).
1
Force should only be applied to the Allen screw 1.
There are 3 different options for assembly
depending on the application:
Assembly
Application
Without measurement chamber and cooling coil
With measurement chamber
With measurement chamber
and cooling coil
Without measurement chamber and cooling coil
Process temperatures 0 to 50°C
It is possible to attach sensor directly in process
No quick assembly/dismantling of testo 6740 required and
flow on sensor is sufficient (1l/min)
Process temperatures 0 to 50°C
Fast assembly/dismantling of testo 6740 required and/or
flow on sensor is insufficient (1l/min)
Process temperatures 50 to 200°C
Compressed air!
Risk of injury!
Warning
Depressurise pipe sections (e.g. compressor
off or use bypass) and aerate before opening.
1 Screw process connection (G½ or NPT½“) into
the matching thread.
The housing can be rotated by 350°. Do not use
force when aligning.
1
2 Set up housing so that the display can be easily
read. Tighten grub screw 1.
3 Complete aeration of pipe section and apply
pressure to pipe section.
4. Initial operation
4.1 Mechanical assembly
11
With measurement chamber (max. 15bar)
1 Check the measuring chamber for soiling and, if
necessary, blow it out before use.
2 Screw in process connection (G½) of the
testo 6741 / 6743 transmitter in measurement
chamber thread.
3 Snap push‑in quick connection of measurement
chamber in standard socket of compressed air
line.
With measurement chamber and cooling coil
(max. 15bar)
1 Check the measuring chamber and cooling
section for soiling and blow out if necessary
before use. Maschinelle Übersetzung
2 Screw in process connection (G½) of
testo 6741 / 6743 transmitter into thread of
measurement chamber.
3 Snap push‑in quick connection of measurement
chamber in push‑in quick connection of the
cooling coil.
4 Snap second push‑in quick connection of the
cooling coil into the standard socket of the
compressed air line.
4. Initial operation
4.2 Electric connection
12
4.2 Electric connection
2
Standard plug
1
We recommend using a 2-core cable with a tight
braided shield and a wire cross-section of 0.2 to 0.5
mm2, such as the enclosed snap ferrite 0204 0201
at a distance of 5 cm from the device plug around
the cable (for cable cross-section 4.5 - 6.0 mm).
3
1 Loosen and remove (1) screw at the back of the
plug and remove plug from transmitter (2).
5
4
6
2 Remove plug socket from the plug housing. To do
this apply a small screwdriver to the point marked
with “lift“ and press out carefully (3).
3 Screw on the cable positioning device (4) and
guide the cables through the plug housing (5).
4 Connect cable ends to the screw terminals of the
plug socket (6):
Plug socket terminals
7
8
9
1:
2:
3:
4:
+ (4 to 20mA), power: 12...30VDC
- (4 to 20mA)
Not assigned
Measuring earth (cable screen)
5 Insert plug socket into plug housing again until
it snaps into place (7) and screw on cable fixing
unit.
6 Attach plug to transmitter (8) and secure with
screw (9)
4. Initial operation
4.2 Electric connection
13
0554.3302 plug (with 2 switch outputs)
We recommend an 8 wire cable with a tightly
braided screen, wire cross-section 0.2 to 0.8mm2.
2
1 Loosen and remove screw (1) at the back of the
plug and remove plug from transmitter (2).
1
2 Tilt the cover of the plug housing at an angle and
remove (3).
3
3 Remove plug socket from the front and the relay
board from the back out of the plug housing.
4 Screw on cable positioning device (4) and guide
cables through the plug housing.
4
5 Connect cable ends to the screw terminals of the
relay board or the plug socket (5):
2
Plug
socket
3
1
I+
Relay board
I-
1 2 3 4 5 6
Flexible lead of relay
board
5
Screen
on PE
The supply lines need
to be galvanically
connected, so connect
either
or
!
Plug socket terminals
1:
2:
3:
I + (4 to 20mA)
I - (4 to 20mA)
(connected to relay
board in factory)
: Put on screen
Relay board terminals
Current
signal and
supply 20
to 28 VDC
1:
2:
3:
4:
5:
6:
20 to 28 VDC
LS +
LS US +
US 0 VDC
4. Initial operation
4.3 Analog output / Limit signal outputs
14
6
6 Push plug socket and plug board into the plug
housing (pay attention to alignment) and close lid.
7
7 Screw on cable positioning device.
8 Attach plug to transmitter (6) and screw into place
(7).
4.3Analog output /
Limit signal outputs
Standard plug/ 0554.3302 plug
Both plug variations have a 4 to 20mA analog
output available in two-wire technology.
x,y connection:
Connection
x Terminal 1
y Terminal 2
x
Max. load RL (external load):
U
0554.3302
Standard
12V
24V
30V
100 Ohm
650 Ohm
950 Ohm
650 Ohm
-
y
RL
4 to 20mA
Power
Standard plug:
U = 12 to 30V DC
0554.3302 plug:
U = 20 to 28VDC
4. Initial operation
4.3 Analog output / Limit signal outputs
15
Limit signal outputs with 0554.3302 plug
Two floating contacts (NO contact) are available.
HYSt, default
setting: 2K
HYSt
LS = On
LS = Off
US = On
US = Off
Definition Lower
Switch (LS),
default setting:
4 °C td
Switching point
LS + HYST,
default setting:
6°C td
Definition Upper
Switch (US),
default setting:
12 °C td
LS
Switching point
US + HYST,
default setting:
14°C td
}
Switch contact closed
}
Switch contact open
Restfeuchte (z. B. als
Drucktaupunkt, °C td)
US
Terminal 2
Terminal 4
Terminal 3
Terminal 5
Max. circuit:
30V DC / 0.5A
Default settings for other parameters (ppm, %RH,
...) See 3.3 Settings, p.8
Example:
- The lower alarm shall be switched at +8 °C td
- The higher alarm shall be switched at +12 °C td
Set these values
- LS = 6 °C td
- US = 10 °C td
- Hyst = 2 °Ctd
- Switching point lower alarm = LS + Hyst = 8 °C td
- Switching point upper alarm = US + Hyst = 12 °C td
16
5. Menu guide
5. Menu guide (0555.6743 / 0555.6744 only)
Display from (see 2)
Display mode 1, 2, 10, 12
Reading and unit alternately / Reading continuously (see 3)
3
4
CodE
Unit
Enter code
Set unit (Unit)
4 digit password, default
setting: 6810
= +1
= next digit
Pressure dew point
°Ctd / °Ftd, atm. dew point
5 °CtA / °FtA, rel. humidity
%rF / %Hr / %rh, absolute
humidity mg/m3 (display: abs)
5 / ppm , tempe­ra­ture °C, °F
v
Select with
Set 4mA value
(S-Lo) 2
Define lower limit of scale 6
= +1
= Next digit
Set 20mA (S-Hi) 2
Define upper limit of scale 6
Return to ProG
Set absolute pressure in
bar (PrES) 5
= +1
= Next digit
Return to Unit
= +1
= Next digit
Display: Min. value (Lo)
Display: Max. value (Hi)
Set code (UCod) 7
= +1
= Next digit
Set delay menu query (Pti)
1s / 3s / 5s / 10s
Select using
De/Activate (dS-1) “display
can be switched off”
Signs and symbols:
1
2
ON = Display can be
switched off
OFF= Display cannot be
switched off
Select using
De/Activate (dS-2)
“Change value/unit”
ON = 6s value, 2s unit
OFF =
Value continuously
Select using
Test analog output (AtES)
-- = No signal
4 = 4mA
12 = 12mA
20 = 20mA
Select using
Activate using
ProG
Change menu using button specified.
Press button briefly.
Save input using
Keep button pressed for 2s.
menu or change menu using
without saving input.
and change
3
17
5. Menu guide
Return to UNIT
ALAr 8
AdJ11
rST
Set lower switching point
(LS) 6
Reference value > - 60°Ctd
(rEF) 9
Carry out reset (rES)
= +1
= Next digit
= +1
= Next digit
Set upper switching point
(US) 6
Return to AdJ
= +1
= Next digit
Set hysteresis value (HYSt)
= +1
= Next digit
Test limit signal outputs
(tESt)
Notes:
1
2
3
-0- = Both operating
points off
-1- = Lower operating
point on
-2- = Upper operating
point on
Select with
Activate with
4
5
Return to ALAr
10
6
7
8
9
11
12
nor = No reset
rS = Reset (return to
default setting))
Select using
Return to rSt
If there are breaks in the input, the system returns automatically
to the display mode after approx. 1min.
In the case of the units ppm and Abs (mg/m3), values are
displayed/entered to the power of ten. Examples:
15E1 corresponds to 15 x 10 = 150, 02E2 corresponds to
2 x 100 = 200, 21E3 corresponds to 21 x 1000 = 21000
Keep button pressed (1s / 3s /5s / 10s, corresponding to setting
in (1), default setting: 5s).
Only with deactivated code (can be set in Prog - UCod menu).
Absolute pressure (can be set in Prog - Pres menu) is included
in the calculation of the ppm value and atmospheric dew point
(°CtA / °FtA).
For negative values: select “-“ at left digit position.
To deactivate codes: Enter 0000. Important: Note down the code
at a suitable point, operation is impossible without a valid code.
Can only be used together with the 0554.3302 plug.
Menu is only available if one of the following units is set: °Ctd,
°Ftd, %rF, %Hr or %rh (can be set in Unit menu). Also see 6.
Adjustment on site, p. 18.
The displayed reading flashes if the scaling limits are exceeded
(can be set in Menu UNIT - S-Lo or S-Hi).
Compare chapter 6.
Display blinks if actual values are below 4mA setting or above
20mA setting.
18
6. Adjustment on site
6. Adjustment on site
One point adjustment by inputting one reference
value
Using one point adjustment, you can enter a
reference value for a working point (e.g. -40°C td)
specified by you. In this way you will achieve a
minimum target/actual deviation from this working
point.
A dew point mirror is ideal as a reference measuring
instrument.
The Adj menu in which the reference value is
entered is only available if one of the following
units is set: °Ctd, °Ftd, %rF, %Hr or %rh (See 5.
Menu guide, p. 16, Unit menu, Setting unit).
Reference value input
Optimum precision is achieved at reference value
-40 °C td. In case low dewpoints (<-25 °C td) are
relevant, it is suggested to avoid reference values
>-30 °C td (else loss of precision).
1 Expose reference measuring instrument and
testo 6740 to identical, constant conditions and
await adjustment time.
2 Measure reference value and compare with
testo 6740 reading.
3 If there are deviations in the values, enter
reference value in Adj menu.
7. Care and Maintenance
19
7. Care and Maintenance
Filter, measurement chamber, cooling coil
If process conditions are oily or dusty, the stainless
steel sintered filter should be cleaned and also the
measurement chamber and cooling coil should be
cleaned if used.
Unscrew/remove filter, measurement chamber
and cooling coil, purge with compressed air or
place in an ultrasonic bath.
Sensor cleaning
During cleaning, avoid touching the sensor at all
costs.
Do not clean the sensor mechanically, as this can
damage the cover electrode.
Screw off filter cover.
Carefully rinse the sensor with isopropyl alcohol
and/or distilled water.
Allow the sensor to dry completely
20
8. Troubleshooting
8. Troubleshooting
Fault
Possible causes
Remedy
Analog output values
- Incorrect scaling or unit
Change scaling or unit in Unit menu
too low/too high
No signal
- Connection interrupted
Check cables
or
- Supply voltage too low
Check power:
- Polarity incorrect Standard plug min. 12VDC
0554.3302 plug: min. 20VDC
Signal >21mA
- Sensor defect (broken). Sensor must be replaced.
Contact your local distributor or
Testo´s Customer Service.
Signal <4mA
- Sensor corroded
Sensor must be replaced.
Contact your local distributor or
Testo´s Customer Service.
Display oF
- No signal from sensor Contact your local distributor or
Testo´s Customer Service.
Displayed reading flashes
- Scaling limits exceeded Change scaling limits in
Unit - S-Lo or S-Hi Menu
If the fault cannot be repaired by following the suggestions given in the above table,
please contact your local distributor or Testo`s Customer service department. For
contact data, see back of this document or web page www.testo.com/service-contact
9. Technical data
9.1 Measurement ranges and accuracies
21
9. Technical data
9.1 Measurement ranges and accuracies
Type of mreasurement
Measurement range
Accuracy
Pressure dew point
-45 to +30 °Ctd
±1 K at ±0 °Ctd
temperature ±3 K at -20 °Ctd
(trace humidity)
±4 K at -40 °Ctd
(at 25 °C)
atm. dew point
-70 to -15 °C td at 30 barrel
cf. pressure dew point temperature
-54 to +10 °C td at 3 barrel
-45 to +30 °C td at 0 barrel
Temperature
±0 to +50°C
±0.5 K
9.2 Additional instrument data
Characteristic
Values
Supply voltage
24 VDC (standard plug: 12 to 30 VDC allowed, 0554.3302 plug: 20 to 28VDC allowed)
Max. load
12 V: max. 100 Ohm, 24 V: 650 Ohm, 30 V: 950 Ohm
Ambient temperature
-20 to +70 °C (process temperature 0 to +50 °C)
Storage/transport temperature -40 to +80 °C
Protection class IP 65
(with plug attached and cable connected)
Rotatability 350°
(display alignment)
Humidity sensor
Testo humidity sensor with logged trace humidity-adjustment at -40 °Ctp / 6 bar
Temperature sensor
NTC
Sensor protection
Stainless steel sintered cap
Pressure resistance
-1 barrel to +50 barabs
Measurement chamber 0554.3303: max. 15barabs
Dimensions
199.5 x 37 x 37 (with standard plug), 203.5 x 37 x 37 (with 0554.3302 plug)
Warranty
2 years
Analog output
Signal
Scaling
Output parameters
Resolution
Accuracy
4 to 20mA, two-wire technology
Standard: 4 to 20 mA = -60 to +30 °Ctd, with freely scalable display
°Ctp, °Ftp, °CtA, °FtA, %RH, ppmv, mg/m3, °C, °F
12 bit
±40µA
Limit value outputs (optional, only with 0554.3302 plug)
Contacts
Lower switching point
(LS + HYST)
Upper switching point
(US + HYST)
2 NO contacts, potential-free, max. circuit 30 V / 0.5 A
+6°Ctd , with display freely programmable
+12°Ctd , with display freely programmable
22
9. Technical data
9.3 Uncertainty pressure dewpoint temperature
9.3 Uncertainty pressure dewpoint temperature
10. Accessories/Spare parts
10. Accessories / Spare parts
NamePart no.
Basic instruments (incl. plug for access line)
with process connection G1/2, without display
0555 6741
with process connection NPT1/2”, without display
0555 6742
with process connection G1/2, with display
0555 6743
with process connection NPT1/2”, with display
0555 6744
Accessories
Cable connection plug for power/analog output 4 to 20 mA, with 2 floating switch contacts and 0554 3302
2 LEDs (limit signal output, alarm output)
Measurement chamber for optimum flow on humidity sensor, max. 15 bar, for thread G½
0554 3303
Cooling coil for process temperatures above 50 °C (up to 200 °C)
0554 3304
ISO calibration certificate for pressure dew point (-40° to 0° Ctp at 6 bar), free choice of points
0520 0116
ISO calibration certificate for pressure dew point at -10° Ctp and -40° Ctp
0520 0136
Power unit (desk-top unit), 100 to 240VAC / 24VDC (350 mA)0554 1748
Power unit (DIN rail mounting), 100 to 240VAC / 24VDC (2,5 A)0554 1749
23
testo SE & Co. KGaA
Postfach 11 40, 79849 Lenzkirch
Testo-Straße 1, 79853 Lenzkirch
Telefon: (07653) 681-0
Fax: (07653) 681-100
E-Mail: info@testo.de
Internet: http://www.testo.com
0970 6740 en 11